Best thing to do for otter is provide the grader with a nice inspection window that is NOT cut into the flank.
I would not recommend rubbing grease into the fur.Dont rub the fur at all.It could induce singe in a raw otter pelt.
Dry the skin under cool conditions,50f or so-no heat,low humidity.Use sawdust when scraping if you handle them on the beam to keep the fur grease free,and dampen your beam with a mist of water before fleshing.
Pin or screen the tail in a natural position,dont pull it short and wide nor long and skinny.